Adjustable gas-engine piston



Oct. 23, 192s. 1,688,792

W. l.. scHoENGARTH ADJUSTABLE GAS ENGINE PISTON Filed April, 1927 In/uente?,

Patented oct. 23, l192s.

WALTER L. SCHOENGARTH, F HURLEY, WISCONSIN'.

. iemIrJs'raBLE GAS-ENGINE IIs'roN.l

Application ined .April 9,1927. serialv NoA 182,396.. f

My invention relates to pistons especially designed; for gas enginesand to that type wherein the skirt of the piston is made to be `adjusted to secure a` close `fit between the piston and the bore of the'ucylinder, thus guarding against leakage and providing vfor maintaining a uniform relationship betweenl the piston and the bore of the cylinder rev gardless of wear, all 'as will bek hereinafter more fully described and claimed.v

parts :L s

Figure 1 1s a transverse sect-lonk through a piston constructed 1n accordance with my said invention taken on the4 dotted line 1 1.-

in Figure 2 ;r

Figure., 2, a cross-section on the dotted kline 2-2 in Figure'l;

ing wedgel by'which the adjustment of the piston is secured; and

Figure 5, a perspective view of a modiiied form thereof. In said drawing, the portion marked 10 in. dicates the piston head, 11 the skirt, 12 bosses for the crank pin bearings, 13 the adjusting wedge and 14 an adjusting screw by which the,position of said wedge is regulated. f

'The general'construction ofthe piston 1n so far asthe head and skirt are concerned is not materially different from that shown in m former Patent No. 1,174,092, granted Mrch 7, 1916, but the present invention relates more to improvements in details whereby a more eiiicient operation is secured.

In the present piston a transverse slot 20 is formed in the oil ring groove for about two-thirds more or less of the circumference of the piston and a longitudinal slot 21 ex-' tends through the skirt-from said horizontal or transverse slotto the bottom` ofthe skirt. On each side of said longitudinal construction shown in Fig. 4, comprisingside members 15 for engagement with the Jpansion of the pistondue to the heatand Figure 3, asimilar view on the dotted' line 3-3 in Figure 1; l ,e i. Figure 4, a perspective View of an expendpanded.

groove 24 and angular` connecting webs 16 and 22v formed integral therewith and yin the mannershown toprovide forv a 'slight lateral compression to; compensate for the exthereby preventing scoring ofthe cylinder.y A horizontal ear 17 extendstoward the interior of the pistonwith a bifurcated inner end with which the adjusting screw 14 engages by a circumferential. grooveunderits head.

l Said adjusting screw is preferably formed with` a circumferential groove adjacent to `the head, whichfits'., between the prongsof saidA bifurcated flange17.v The otherfend of said,'adjust-ing` screw is' screw-threaded and engages ina screw-threaded boss `18 formed ont-he sider ofthek piston headl and a jambnut 19is mounted adjacentsaidboss on the under. side thereof." y l. j

In Fig. 5i"s`illustrated a form of wedge 13 which is solidi or-non-yielding. .This `form of wedge requires very accurate adjustment to ybe properly set .when the `,piston has, ex-

the longitudinal groove cutting theiskirt in two .on one side, is made flexible and capable of easy and ready adjustment. The turning of screw 14 will,` as will be readily understood, operate through the movement of wedge 13 to expand the skirt to obtain a snug t between the skirt of the piston and the bore of the cylinder. It will also be seen that 'as the part'slweara slight turn of' screw 14 by a screw driver inserted in the slot in its end will operate to expand the skirt sufciently to maint-ain the desired relationship between thevparts.

By the special construction of the expanding wedge 13, whereby it is made more or less resilient, the diameter of the skirt becomes within limits automatically adjust-i100 able so that if the piston should be too .closely adjusted when the motor is cold, it

might, bind on the cylinder wall unless capable of vielding somewhat to the longitudinal slot',u all of' which is provided for by 105 this special form of wedge. The wedge therefore becomes a safety device to prevent scoring the .Wall of the cylinder.

It will be understood. of course, that various modifications may be made in the con- 1,10v

d struction` of this device lwithout deplarting of the circumference of thepiston, said skirt beiner formed with another slot extending long1tudinally thereof from the transverse slot to the bottom of the skirt and having bearing surfaces formed on each side thereof and extending substantially the length "of the skirt, and curved adjusting wedge mounted between said bearing surfaces, substantially as set forth.

2. A piston comprising a head and a skirt, a threaded boss on the head of the piston, said skirt being formed with a longitudinal slot wherebyl it is adapted to be expanded,

.bearing surfaces formed on each side 0f said slot and extending at an angle to each other, a wedge mounted between said bearing surfacesand an adjusting screw engaging the said wedge and engaging with said threaded boss, whereby the ad ustment is effected, substantially as set fort v3. A piston comprising a head, a skirt formed in piece therewith but partly severed therefrom by a transverse slot-adjacent said head and with another slot running longi- Losanna tudinally ofthe skirt' said transverse -slot to the bottom ofthe skirt, and a resilient wedge adapted -to bear between arts of the skirt .on opposite sides of the ongitudinal slot for adJusting the diameter Aof said skirt, sustantially as set forth'.

4. A piston comprising a head and a skirt, rsaid skirt being formed with a. longitudinal slot to permit 1t to be expanded, a bearing surface on said skirt at each side of said slot, said'bearing surfaces being disposed at an angle to each other, an elongated wedge mounted between said bearing surfaces and having a bifurcated-fiange and an adjusting screw carried by' said head and having ya slotl for the reception of-said ange, substantially as setl forth.

5. The combination with a longitudinal y Slotted piston skirt, ofa pair of projections mounted-on said skirton opposite sides of ,the slot and extending longitudinallyvof the skirt-a major portion of its length, and a.

wedge of a len h substantially corre onding to the lengt of the projections an disposed between the same for adjustin the diameter of the skirt, said wedge ing curved to conform tothe curvature ofthe skirt, substantially as set forth. v

AInf witness whereof,l I have hereunto set my handat Hur1ey,-Wisconsin this 6th day of April, A. D. nineteen hundred and twenty-seven. J

WALTER L. .soHoENGAi-zrn. 

